main(){
//字符串类型
String name = "张三";
print(name);
//字符串拼接
String name2 = "李四";
String name3 = name+name2;
print(name3);
//换行
print('''hello world
$name3''');
print("hello \n world");
//数字类型
num a = 10;
print(a);
a = 11.11;
print(a);
//int 类型
int b = 10;
print(b);
//double 类型
double c = 10.10;
print(c);
//bool 类型
bool d = true;
print(d);
d = false;
print(d);

print(a<=11?'成年':'未成年');



}
